Rotor Interest Posted March 6, 2013 Report Share Posted March 6, 2013 Does anyone know if there are manufacturers of composite rotor hubs, except for Bell? Looks like Bell has developed them for the H-1, but are there other rotorcraft with all composite rotor hubs, and does Bell supply these as well? 1 Quote Link to comment Share on other sites More sharing options...
JDHelicopterPilot Posted March 7, 2013 Report Share Posted March 7, 2013 EuroCopter has what is called a star flex on their Astar. It is basically fiberglass. Quote Link to comment Share on other sites More sharing options...
Rotor Interest Posted March 7, 2013 Author Report Share Posted March 7, 2013 Thanks JD. Is the term "fiberglass" synonymous with the term "composites", when it comes to aircraft/rotorcraft components? Quote Link to comment Share on other sites More sharing options...
JDHelicopterPilot Posted March 8, 2013 Report Share Posted March 8, 2013 Never really thought about that. I don't really know. Just that the star flex is not your typical hub you would see. 1 Quote Link to comment Share on other sites More sharing options...
RkyMtnHI Posted March 8, 2013 Report Share Posted March 8, 2013 I have a timed out Starflex in my office and can post a photo of it if you like.. Quote Link to comment Share on other sites More sharing options...
ridethisbike Posted March 8, 2013 Report Share Posted March 8, 2013 I would like to see that very much, por favor. Quote Link to comment Share on other sites More sharing options...
Rotor Interest Posted March 8, 2013 Author Report Share Posted March 8, 2013 Yea, that would be great. Thanks. Quote Link to comment Share on other sites More sharing options...
Wally Posted March 8, 2013 Report Share Posted March 8, 2013 Thanks JD. Is the term "fiberglass" synonymous with the term "composites", when it comes to aircraft/rotorcraft components? "Composite" is generic to describe combination materials substituted for conventional metallic construction. It used to describe the 'rubber'/stainless steel' sandwiches replacing dampers and other bearings, carbon fiber, fiber glass and various other structural materials. The idea is that by carefully combining materials with different properties in light of end engineering requirements one eliminates some of the drawbacks of metallic parts.Never heard described as such, but the Dehavilland Mosquito of WW II is an outstanding example of a composite use- plywood. 1 Quote Link to comment Share on other sites More sharing options...
RkyMtnHI Posted March 9, 2013 Report Share Posted March 9, 2013 Here ya go.. Quote Link to comment Share on other sites More sharing options...
iChris Posted March 9, 2013 Report Share Posted March 9, 2013 (edited) Does anyone know if there are manufacturers of composite rotor hubs, except for Bell? Looks like Bell has developed them for the H-1, but are there other rotorcraft with all composite rotor hubs, and does Bell supply these as well?  Soft-in-plane rotor system. What? - Started by SBuzzkill, Jan 21 2011  As stated in the above post, the most notable is Aerospatiale/Eurocopter with the AS350 Astar, AS365N Dauphin 2, and EC 155B. MD helicopters is also in the running with the MD900N with a composite flexbeam main rotor hub that replaces the normal hinges with a fiberglass/epoxy flexbeam that twists and bends to accommodate the blade motions. Other companies have undertaken composite hub programs in experimental design such as Sikorsky, Lockheed, United Technologies Corporation, Costruzioni Aereonautiche Giovanni Agusta, and Messerschmitt-Bölkow-Blohm (MBB)/Boeing to name a few. The first structural components made of composites were fiberglass rotor blades pioneered by MBB in West Germany in the early 1960s The Sikorsky/Army project looked into composites for the H-60 Advanced Composite Rotor Preliminary Design. The following were some of the design goals: 1. Make maximum use of existing BLACK HAWK rotor head components. 2. Achieve an acquisition cost savings of 25% and an overall reduction in life-cycle costs. 3. Obtain a 15% reduction in weight. 4. Obtain a 98% reduction in radar cross section in the 5 to 15 GHz radar frequency range. 5. Improve the damage tolerance as compared to a titanium hub and design the hub to be field repairable for external damage. 6. Design the hub so that no in-flight testing is required to track and balance when the titanium rotor hub housing is replaced with the composite and so that no in-flight tracking is required when interchanging blades on the composite hub. “The new rotor system is not without its problems, however, he admits. Several rotor components are falling far short of the original 10,000hr goal. The rotor cuff, for example, must be replaced after 1,200 flight hours. The programme will redesign the cuff and yoke to improve durability. However, Hewson adds: "It remains a very high performance rotor head with very high response rates and minimal recurring maintenance." Col Harry Hewson, H-1 upgrades programme manager for the US Naval Air Systems Command http://youtu.be/PaSm3cor3wg Edited March 10, 2013 by iChris Quote Link to comment Share on other sites More sharing options...
Wally Posted March 10, 2013 Report Share Posted March 10, 2013 Neat animation of the Starflex.I wonder why the spherical bearings/frequency adapter (terminology? I just point and ask the mech "Is it s'posed to look like that?") at the tips of the Starflex were ommitted. The three-pointed star installed is visually continuous from the root to the blade tip via that bit. Quote Link to comment Share on other sites More sharing options...
iChris Posted March 10, 2013 Report Share Posted March 10, 2013 (edited) Neat animation of the Starflex.I wonder why the spherical bearings/frequency adapter (terminology? I just point and ask the mech "Is it s'posed to look like that?") at the tips of the Starflex were ommitted. The three-pointed star installed is visually continuous from the root to the blade tip via that bit. You’re correct; the animation of the Starflex doesn’t show much of the Spherical Bearings. It also doesn’t show that the points of the stars fit into the Frequency Adapters. click to enlarge image   Edited March 10, 2013 by iChris 1 Quote Link to comment Share on other sites More sharing options...
Rotor Interest Posted March 12, 2013 Author Report Share Posted March 12, 2013 Thanks to all, for the feedback!! Quote Link to comment Share on other sites More sharing options...
Rotor Interest Posted March 12, 2013 Author Report Share Posted March 12, 2013 Chris, thanks a million. I spent additional time tonight looking at all those sources you referenced, that's great info. I appreciate it! Quote Link to comment Share on other sites More sharing options...
chris pochari Posted May 5, 2017 Report Share Posted May 5, 2017 You’re correct; the animation of the Starflex doesn’t show much of the Spherical Bearings. It also doesn’t show that the points of the stars fit into the Frequency Adapters. click to enlarge image    The Star flex only flaps up and doesn't lead lag right? Quote Link to comment Share on other sites More sharing options...
Wally Posted May 6, 2017 Report Share Posted May 6, 2017 The Star flex only flaps up and doesn't lead lag right?The Starflex allows individual blade "hunting". Quote Link to comment Share on other sites More sharing options...
iChris Posted May 8, 2017 Report Share Posted May 8, 2017 (edited) The Star flex only flaps up and doesn't lead lag right? As stated above, it’s allowed to Hunt (Drag), Flap, and Feather (Pitch change)  Starflex Hub Dynamics  Edited May 8, 2017 by iChris Quote Link to comment Share on other sites More sharing options...
Guest pokey Posted May 8, 2017 Report Share Posted May 8, 2017 the star actually only flaps up and down, the lead/lag is absorbed by the elastomeric bearing, as is also the feathering. It is rigid in it's 'hunting' (other term for lead/lag) Quote Link to comment Share on other sites More sharing options...
Wally Posted May 8, 2017 Report Share Posted May 8, 2017 (edited) The star itself flexes to allow vertical movement of each blade. There were cracking issues with the early Starflex arms. The laminated spherical stop bearing is at the inboard end of the blade/sleeve. Sleeves are the more or less rectangular structures that extend above and below the Starflex arms from the 'hub' area to the outboard end of the Starflex arm and blade root and carry pitch change to blade. these transmit the centrifcal forces to the Starflex and move wuth the blade. The laminated is where the bearing for the pitch horn effects. Rougly cone shaped. The frequency adaptor at the ourboard end of the Starflex is where the hunting/lead-lag forces are absorbed and damped. The Starflex arm ends with a ball and socket arrangement into the frequency adaptor block, this allows the blade free pitch change and the frequency adaptor absorbs/dampens only the fore and aft movement of the blade. The terminology always confused me, in that the frequency adapter has a ball and socket while the sperical stop bearing is a cone... Just look for worms and cracks in the laminated rubber, and PAINT on all fiberglass. Oh yeh, check the safety pins locking the blade pins. Edited May 8, 2017 by Wally Quote Link to comment Share on other sites More sharing options...
chris pochari Posted May 9, 2017 Report Share Posted May 9, 2017  As stated above, it’s allowed to Hunt (Drag), Flap, and Feather (Pitch change)  Starflex Hub Dynamics  Oh ok I guess I got confused because it said "rigid in plane drag wise" http://imgur.com/pa8BRDX Quote Link to comment Share on other sites More sharing options...
Guest pokey Posted May 9, 2017 Report Share Posted May 9, 2017 Oh ok I guess I got confused because it said "rigid in plane drag wise" Â Â The star itself is rigid in plane drag and feather/wise. Once the other parts of the rotor head are added, it becomes a fully articulated rotor system that is allowed to flap, feather & lead/lag. That being said, it is also prone to ground resonance and must use some sort of landing gear damping system also. Quote Link to comment Share on other sites More sharing options...
chris pochari Posted February 23, 2018 Report Share Posted February 23, 2018 Porcher industries is supplying a composite hub for the new H160. Quote Link to comment Share on other sites More sharing options...
500E Posted February 24, 2018 Report Share Posted February 24, 2018 http://www.porcher-ind.com/en/news/world-s-first-carbonpeek-helicopter-rotor-hub-at-jec-world-2017_50.html Quote Link to comment Share on other sites More sharing options...
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